This topic came up the other day, in a Raidcall discussion with Spartan, myself, Finalfab and Izzy. Sadly my memory went all futzy, so I swore I recalled something different than what actually occured (it happens, I play way too many MMOs with varying mechanic differences for my memories not to get melded and confused). So I did a little digging, and managed to find the source of my memory, but it was from back in Beta, not a post-release nerf like I'd thought. My bad.
So, here is the AOE rule of the GW2 skill system:
Quote by Jon Peters: (circa May 2012)
This is a general rule of our skill system. AoE attacks hit up to 5 targets. AoE buffs or heals can heal up to 5. We cap it at 5 because its the party size and lets us reign in the balance on AoE without impacting most normal situations. WvW is the one place where this shows up, but we believe the alternative is worse. Hope this helps…
It prioritizes targets.
1) Your selected target assuming they are in range.
2) enemies based on proximity to you.
1) party members based on proximity to you
2) non party members based on proximity to you.
Hope that helps.
So, yea. I hope that helps folks understand how to use their AOE fields a bit more efficiently, too. I found the proximity rules interesting, I was not aware of those. I always thought that maybe it was a random target each tick, up to 5 max or something. Nope, I was wrong.